Caretaker head coach Lionel Scaloni had already led them to a friendly victory over Guatemala and draw with Colombia, and in the friendly Super Clasico tournament that also involves Saudi Arabia and long-term rivals Brazil, he oversaw another encouraging performance.
In the absence of Lionel Messi – still to confirm if he will continue playing for his country – Sergio Aguero and Angel Di Maria, goals from debutants Lautaro Martinez and German Pezzella, and Roberto Pereyra and Franco Cervi demonstrated their dominance.
Martinez’s came in the 18th minute, when he met a fine, left-wing cross from Marcos Acuna to head in from six yards.
Paulo Dybala had just threatened to double their lead when, in the 53rd minute, he created a chance for Pereyra. After beating two defenders he found his team-mate, who then routinely finished into the bottom corner.
Victory already felt secure when, in the 83rd minute, Scaloni’s team scored again. From Cervi’s corner, Eduardo Salvio nodded on to Pezella, who in turn headed beyond Iraq goalkeeper Jalal Hassan Hachim.
Cervi scored Argentina’s fourth and final goal – and the most impressive of the lot – in the second minute of second-half stoppage time.
Carrying possession for 25 yards in the same way Argentinians have so often seen Messi, he closed in on Hachim and finished beyond the goalkeeper’s right and into the corner.
They next face Brazil on Tuesday.